With the continuous development of display technologies, display devices (such as displays) have increasingly more functions. The original display devices only had a display function and displayed a black and white image. The current display devices not only display a colorful image but have also become more intelligent. For example, in a current touch-screen mobile phone, a user can operate and control related functions of the mobile phone by touching the screen, which provides convenience for the user's operation.
At the present, the functions of three-dimensional imaging and gesture recognition have received extensive attention. For example, in a VR (Virtual Reality) game, by recognizing or tracking changes in a user's gestures, and simulating the user's hand into a three-dimensional image to be displayed in a virtual scene, the user can intuitively participate in the game, thereby bringing fun to the user.